Envelope opening machine



May 9, 1939.

E. J. DUMMER Er A1.

ENVELOPE OPENI NG` MACHINE Original Filed Dec. 24, 1936 2 Sheets-Sheet lMay 9, 1939- E. J. DUMMER E1-v AL 2 2,157,232

ENVELOPE OPENING MACHINE Original Filed Dec. 24, 1956 2 Sheets-Sheet 2 l4 INVENTORS Edward dja/WWW' a/fd' ZeZ @ay Patented May 9, 1939 ENVELOPEOPENING MACHINE Edward J. Dummer and Azel Gay, Rochester, N. Y.,assignors to Multpost Co., Rochester, N. Y., a corporation of New YorkOriginal application December 24, 1936, Serial No. 117,486. Divided andthis application January 22, 1938, Serial No. 186,357

2 Claims.

Our present invention relates to paper feeding and cutting machines andmore particularly to envelope or mail opening machines of the type inwhich the letters either piled or singly may be run rapidly through andone of their marginal edges neatly slit to just remove the fold withoutinjuring the contents, and it has for its object to provide a simple,efficient and improved machine of this character that may beconveniently operated at high speed and capacity and yet with surety ofaccurate performance.

This application is a division of our prior application, Serial No.117,486, led December 24, 1936, in which other features of the machineare disclosed and claimed, but the improvements herein concerned arerestricted to the feeding mechanism whereby the envelopes are rapidlypassed in succession past the cutting means and ejected from themachine. They relate to the provision of means adapted to withstand thewearing effects of the envelopes that will function to hold theenvelopesecurely against its guide at the cutting point so that the cutor shear will be uniform at all times and each envelope will becompletely opened along the full extent of one edge but with such anicety that the contents will not be threatened with damage.

To these and other ends, the invention resides in certain improvementsand combinations of parts, all as will be hereinafter more fullydescribed, the novel features being pointed out in the claims at the endof the specification.

In the drawings:

Fig. 1 is a front elevation of a letter opening machine constructed inaccordance with and illustrating one embodiment of our invention;

Fig. 2 is a top plan view thereof;

Fig. 3 is a vertical section taken substantially on the line 3-3 of Fig.1 and viewed in the direction o-f the arrows;

Fig. 4 is a top plan view similar to Fig. 2 but with the bed plate andcasing shell removed to disclose interio-r parts, particularly in themounting of the feed belt; and

Fig. 5 is an enlarged detail sectional end view of the presser feetillustrative of their action on a passing envelope.

Similar reference numerals throughout the several views indicate thesame parts.

Referring more particularly to the drawings, I indicates a preferablycast base having end walls Ia and a partition-like central framework 2rising therefrom. At the front is suitably secured a cover plate 3 andat the rear a cover plate 4 together constituting a casing within whichthe interior mechanism is housed. At the front a shelf-like plate 5constitutes the bed along which the envelopes are fed and operated upon.Rising from the rear wall of this bed plate at the left end thereof inFig. 1 is a flange 6 constituting a general rear guide wall. Atransversely extending vertical plate 1 has a flange by which it issecured to the frame 2 at 3 and constitutes a gate beneath which theenvelopes are fed. They are stacked on this left hand or feed end of thebed plate 5 in an inclined pile, the regularity of which is establishedby the guide wall 6 and the said gate 1. The downward inclination of thefeed of the lower envelope is established by a shed 9 secured to thetable by a screw IB passing therethrough and into a lug II on theadjacent base end Ie.

At the right hand end of the table, the frame 2 is provided with abearing I2 in which turns a shaft I3 having at its rear end a drivenpulley I4 and belt I5 by which it is turned from the driving pulley I6of a motor Il mounted on the base. The shaft I3 extends through theframe partition 2 and at its forward end is a hub IB against the rearside of which is clamped securely by a nut I9 a slitting knife 20. Ahousing 2ll2u open sufliciently at the bottom only to admit a guidingmeans and the envelopes, covers and protects this knife, the same beingheld to the frame wall 2 by screws 2Gb. Against the front side of thehub is similarly secured by a nut 2| a grooved pulley 22. Anothergrooved idler pulley 23 is mounted on a stud 24 on the frame partition 2and over the two pulleys passes an endless feed belt 25. This feed beltis preferably of rubber and circular in cross section. Its upper reach2E travels in slot 2I on the bed plate 5 and projects just partiallyabove the same so as to take sure frictional Contact with an envelope onthe bed while the latter is still maintained in a substantially flatcondition.

Above the bearing I2 is a similar bearing 28 on the frame 2 containing astud shaft 29. On the outer or forward end of this stud is a hub 3Gagainst which there is clamped by a nut 3l an upper companion slittingknife 32 cooperating in the overlapping manner best shown in Figs. 3 and5 with the driven knife 2). The stud 29 is hollow and contains a spring33 that reacts against a plate 35 secured to the end of the bearing boXby two screws 35. The knife 32 is thus urged forwardly continuously bythe spring against the driven knife 20 to itself be frictionally drivenby the latter.

As best shown in detail in Fig. 5, an extension 36 on the end of theback plate or guide 6 of the bed plate 5 projects toward the knives andhas a tapered end 31 that enters between them at their intersectionrunning as closely as possible to the bite or cutting point of theblades. This extension is V-shaped in cross section, but the bottom atthe inside apex is definitely flat, as indicated at 38 in Fig. 5, liesin the plane of the guide wall 6 and this plane is sufliciently back ofthe cutting plane defined by the contacting surfaces of the knives tocut off the fold of the envelope edge back the desired distance.

As so far described, in operation, the under most letter of a pilesquared against the back wall 6 and the gate 'l touches or is urged bythe operator against the belt 25. It is carried under the gate and thefrictional hold of the belt thereon causes it to overcome the retardinginfluence of a spring finger 42 on the far side of the gate having anotch 43 therein (Fig. 2) to accommodate the belt. The nger has arounded lower edge which, however, arrests the envelope next above untilthe rst one, whose frictional contact might otherwise carry it with it,has passed on, This adjacent one in turn contacts the superior frictionof the feed belt and is next fed forward. The latter carries eachenvelope along the edge guide through the knives which slit the foldthereof and then it passes out at the right end of the machine in openedcondition.

At the cutting point, the envelope is held to the knives in oneconstruction by compressor feet and 5|, best shown in Figs. 1, 3 and 5.These are jointly notched at 52 to span the feed belt and are pivotedupon a stud 53 projecting from the vertical frame piece 2. The innerfoot 50 is provided with a lug 54 engaging beneath the foot 5|. Thelatter is pressed downwardly by a spring 55 coiled about the stud sothat through the lug it also presses down companion foot 59 although thelatter may rise independently.

It is, of course, important that as the envelope enters the knives itsedge should be firmly and evenly pressed against the wall 38 of the edgeguide so that the fold thereof will be uniformly and evenly sheared offto exactly the desired extent. This, in the practice of our presentinvention, is insured by the following provisions: In the first place,the direction of travel of the upper reach 26 of the belt is notstrictly longitudinally of the bed but converges inwardly from pulley 23to pulley 22. In addition to this, the axis of pulley 23 is cocked intwo planes intersecting the plane of the axis of pulley 22, as clearlyappears in Fig, 4, that is, the stud is tilted downwardly and alsolaterally bringing the pulleys out of line on two angles. The result isthat the reach 26 ofthe belt twists or rotates on its own geometricalaxis toward the knives as it passes from the one pulley to the other inthe feeding direction, as indicated by the arrows in Fig. 4. Itsfrictional effect on the envelope is, therefore, both to convey it in astraight path and to urge it laterally toward the knives and against theedge guides 36.

This latter function develops operatively from the fact that the upperreach 26 of the belt extends along and contacts uninterruptedly theentire length of a small envelope and the greater portion of the lengthof a large envelope. Hence, its frictional effect thereon is uniformand, without tendency to twist in its horizontal plane, the envelope isurged in parallelism to and straight against its cutting guide, thefrictional force thereafter maintaining it under some pressure againstthe guide and just within the cutting plane of the knives.

rlhis cooking of the rear or idle pulley performs another function inconstantly and uniformly rotating the belt on the geometric axis of itsupper reach. Paper is surprisingly abrasive, especially with respect torubber. If the belt did not thus rotate and the envelopes travelledconstantly on one of its tangetial lines, they would soon wear a flatface thereon, rapidly reducing the necessary degree of projection of theupper reach of the belt above the surface of the bed plate. But withthis bodily rotation, such wear is distributed evenly throughout thewhole circumferential surface so that the reduction in thickness fallsslightly upon all diameters instead of being ccncentrated upon one.

A belt feed constructed in accordance with our invention will,therefore, be found to increase the life of the belt as well asperforming the desired guiding function with respect to the envelope atf the cutters.

We claim as our invention:

1. In an envelope opening machine, the conlbination with a bed, a knifearranged laterally thereof and an edge guide for the envelopesassociated with the knife to direct the edge of an envelope in thecutting plane thereof, of an endless conveyor belt having a reachthereof extending along and partially above the surface of the bed, saidbelt being cylindrical in cross section, a-mounting for the beltembodying two pulleys, one of which has an axis cocked in two planesrelatively to the cutting plane to give the belt a pronounced rotationon its longitudinal axis while travelling between the pulleys andcontinuously urge an envelope toward the edge guide, and means fordriving the pulleys.

2. In an envelope opening machine, the combination with a bed, a knifearranged laterally thereof and an edge guide for the envelopes asysociated with the knife to direct the edge of an envelope in the cuttingplane thereof, of an endless conveyor belt having a reach thereofextending along and partially above the surface of the bed, said beltbeing cylindrical in cross section, a mounting for the belt embodyingtwo pulleys, one of which has an axis cocked in two planes relatively tothe cutting plane, means for driving the pulleys, a yielding presserfoot adapted to engage the edge portion of the envelope at the cuttingpoint, and a companion presser foot adapted to yieldingly engage thebody of the envelope so that the envelope is bent around the rotatingbelt.

EDWARD J. DUMMER.

AZEL GAY.

